Reference no: EM132804153

Question 1

A) Find the completely reduced rate of formation of HBr for the following mechanism.

         Br₂ + M  ↔ 2Br + M         k₁ and k_-1 for forward and reverse reaction
         Br + H₂ ↔  HBr + H         k₂ and k_-2 for forward and reverse reaction
         H + Br₂ →^k3 HBr + Br

Specifically state the rate constants.

B) Propose a mechanism for the reaction:

H₂O₂ + 2H⁺ + 2I^- → I₂ + 2H₂O

For the rate r = k[H⁺][H₂O₂][I^-]

C) Apply the Steady-State approximation to the Br- catalyted reaction we discussed in class and compare the new rate equation to the original.

HNO₂ + 2H⁺ + C₆H₅NH₂ C₆H₅NH₂ + 2H₂O r = k[H⁺][HNO₂][Br⁺]

Question 2
Assume the first step is a catalyst mediated reaction. The reactor runs at 350 K and 1 atm and only 1 molecule per mol will collide with an active site, of with 1 in 100 will stick to the surface (assume kinetic theory). Upon bonding to the surface, the molecule rapidly decompose. Calculate the rate of (H₂O)₅CrR²⁺ decomposition per unit surface area and length of a PFR reactor that is 5 cm in diameter for 87% conversion at a flow rate of 1 cm s^-1.

Question 3
Unfortunately, The SCN group can react with the (H₂O)₅CrR²⁺ and extract an ethoxy molecule which poisons the catalyst in an elementary reaction. What factor would you chose to maximize product? Set up the equation for the critical dimension(length/volume/concentration) in terms of symbols (k₁, k₂, []), etc..), do not solve.

Question 4 California Professional Engineering Exam

Compound A undergoes a reversible, elementary isomerization reaction. A ↔ B. over a metal catalyst. A and B are liquid, miscible, and nearly identical density. The equilibrium constant for the reaction is 5.8. In an isothermal fixed bed reactor with no backmixing, a feed of pure A undergoes a net conversion to B of 55%. If a second identical reactor is placed downstream, what is the overall expected conversion when:
A) The reactors are in series?
B) The products are separated and only unconverted A is fed into the second reactor?

Question 5

Develop the solution for the following problem but do not solve.

The following reactions take place in the liquid phase

A + B → 2C r_tC = k_1C[A][B]; k_1C = 0.0.043 dm³/mol s at 400 K
2B + C → D r_2D= k_2D[B][C]; K_2D= 0.4dm³/mols exp [5000 K (1/500 - 1/T)]

The concentrations of the four molecules were measured at the point where T is maximum and found to be [A]=0.1. [B]=0.2. [C]=0.5, and [D]=1.5 in mol/dm³. The overall heat-transfer coefficient times the heat-exchanger area per unit volume (UA) is 10 cal/s dm³ K and an equimolar feed rate for A and B at 10 mol/s. What is the activation energy of Reaction 1?

C_PA = C_PB = C_PC=20 cal/ mol K; C_PD 90 cal/mol K: C_P1 100 cal/mol K

ΔH_1A° = -50 kcal/ mol A: ΔH_2B° = 5 kcal/ mol B